The present invention relates to permanently moldable structured sheets of textile materials which are reinforced and rendered permanently moldable by an aqueous synthetic resin dispersion.
The structured textile sheets of interest include, inter alia, needlefelt carpets used in automobile manufacturing.
Since such needlefelt carpets are nonwovens, they are customarily reinforced by synthetic resin dispersions, such as aqueous dispersions of styrene/butadiene copolymers, which may be carboxylated, as well as of acrylates, vinyl esters, etc. Such aqueous dispersions are described in F. Holscher/H. Reinhard, Dispersionen synthetischer Hochpolymerer, Springer Verlag Berlin-Heidelberg-New York (1969), Vol. I+II and elsewhere.
In addition, they must be capable of being molded three-dimensionally for installation in automobiles, so that they conform to the generally curved shapes of the underlying surfaces, for example, fenders, universal shaft wells, etc. For this purpose, they must be permanently molded. As a result, such ready-for-use carpets are provided with an undercoating made of a polyethylene powder. The coating enables permanent forming of the carpets or other nonwoven textile sheets.
Such permanently formable needlefelt carpets possess two essential disadvantages. Their manufacture is expensive because of the aforementioned two manufacturing steps (reinforcing and undercoating), especially since these processes represent two entirely different techniques. Moreover, because of the poor adhesion displayed by the backing of polyethylene the needlefelt carpets cannot be joined to underlying surfaces by gluing in a practical manner. To overcome this disadvantage, a rayon mat must be inserted in the sintered polyethylene to enable gluing of the tufted mat carpets.